| 查看: 522 | 回复: 4 | |||
[交流]
Everyday News-NASA Mission Finds Fewer Near-Earth Asteroids Than Expected
|
|
Bad news for little princes—there may be fewer Earth-neighboring asteroids for them to live on than thought. According to results released today by NASA's Wide-Field Infrared Survey Explorer mission, an infrared satellite that's been keeping its eye on asteroids zipping within 200 million kilometers of Earth's orbit, there are close to 20,000 near-Earth asteroids between 100 meters and 1 kilometer in diameter (shown on left). That's down from old guesses of about 35,000 (right). And nearly 15,000 of those rocks, which are big enough to crush an entire city, have yet to be discovered. The researchers also confirmed that astronomers have identified more than 90% of the nearly 1000 big asteroids of the dino-extinction variety. That's too late for Tyrannosaurus rex but perhaps not too late for us. So maybe we ARE alone.  |
回复此楼» 猜你喜欢
一志愿中国海洋大学，生物学，301分，求调剂
已经有6人回复
-
081700化工学硕调剂
已经有3人回复
-
材料学硕318求调剂
已经有4人回复
-
329求调剂
已经有4人回复
-
一志愿吉林大学材料学硕321求调剂
已经有11人回复
-
一志愿苏州大学材料求调剂，总分315（英一）
已经有3人回复
-
0703化学调剂
已经有14人回复
-
320求调剂0856
已经有3人回复
-
307求调剂
已经有9人回复
-
288求调剂
已经有15人回复
2楼2011-10-01 22:10:32
my bandeng 3楼2011-10-01 22:13:27
★
xia_chong(金币+1): Hello! Welcome to English Cafe! 2011-10-02 14:23:03
xia_chong(金币+1): Hello! Welcome to English Cafe! 2011-10-02 14:23:03
 |
4楼2011-10-02 11:40:54
xia_chong
金虫 (文坛精英)
- ESEPI: 43
- 应助: 0 (幼儿园)
- 贵宾: 1.591
- 金币: 10270.8
- 散金: 2377
- 红花: 34
- 沙发: 160
- 帖子: 12455
- 在线: 1941.8小时
- 虫号: 804303
- 注册: 2009-07-06
- 性别: GG
- 专业: 粒子物理学和场论
- 管辖: English Cafe
5楼2011-10-02 14:22:44
